Exemplary embodiments of the present invention relate to a method for assembling motor vehicles.
European patent document EP 0 171 576 A1 discloses a method for the assembly of motor vehicles in which a floor module in the form of a load-bearing chassis is provided, onto which a non-load-bearing structure is placed. The load-bearing floor module having a frame is thus equipped with several seating units as well as a drive train and a chassis, before the structure is placed onto the floor module.
It is generally known from the series construction of motor vehicles, which, by contrast with the motor vehicle according to European patent document EP 0 171 576 A1, typically have a shell or a body in self-supporting design, to prefabricate the drive train and the chassis and assemble them on a driverless transport system. Parallel to this, the shell of the motor vehicle is typically provided with an interior installation in a main assembly line, after which the shell is connected to the drive train and the chassis in line with the so-called marriage.
Furthermore, German patent document DE 37 07 684 A1 discloses a module construction for a vehicle having several individual modules, wherein a base platform is used as a module. Here, the vehicle only has the desired properties for a vehicle body, such as crash resistance and carrying capacity, after assembly, since each individual module contributes to the carrying capacity of the entire vehicle.
Furthermore, German patent document DE 10 2007 047 037 A1 discloses a motor vehicle body, wherein the rear section of the body is configured in such a way that one or more cross-members with structural units arranged modularly thereon can be incorporated into the body according to the currently desired equipment.
Moreover, German patent document DE 101 54 353 A1 discloses a modular vehicle construction, wherein the vehicle chassis has a frame, to which a shell for receiving an energy source to drive a drive system is connected.
Overall, the problem arises in the series construction of personal motor vehicles that, at this stage, a plurality of vehicle variants arises, in particular due to the fact that different drive concepts are offered. Drive concepts are to be understood as, in particular, various drive systems for the motor vehicle, which use different energy sources, so, for example, combustion engines, gas engines, electric engines, fuel cell drives or hybrid drives.
In the current process for assembling motor vehicles, this requires that many assembly steps, which are accordingly different as a result of the different variants, must be carried out within the main assembly line.
Exemplary embodiments of the present invention provide a method for the assembly of motor vehicles by means of which a simplified assembly can be implemented, in particular with the main assembly line.
To create a method of the type cited above, by means of which the assembly of the motor vehicles within the main assembly line is considerably simplified, provision is made according to the invention for the floor module to be pre-assembled in a first pre-assembly process along a separate pre-assembly line and for the drive train and the chassis to be pre-assembled in a second pre-assembly process along a further, separate pre-assembly line, whereupon the floor module, the drive train and the chassis are combined in an assembly region and then connected to the shell of the motor vehicle, wherein constructional units of the floor module, the drive train and the chassis are connected to one another after the combining before being introduced into the shell. In other words, provision is made according to the invention to pre-assemble the floor module on one side and the drive train and chassis on the other, to combine these and then to arrange them on the shell of the motor vehicle. Furthermore, constructional units of the floor module, the drive train and the chassis are connected to one another after the combining within the so-called engagement. In other words, provision is preferably made for the floor module on one side and the chassis and drive train on the other to be connected with respect to one another after the engagement in such a way that these are already in an operative connection with respect to one another at least to the greatest extent possible before the connection to the shell of the motor vehicle—the so-called marriage.
Indeed, the floor module, the drive train and the chassis are subjected to a considerable variance as a result of the different drive variants of the motor vehicle, which can be counteracted particularly favorably by carrying out corresponding pre-assembly processes. Thus, for example, the floor module can be equipped with corresponding equipment with a plurality of variant-specific constructional units, which, for example, are delivered sequentially, in order that there is an optimal adjustment to the drive concept in the pre-assembly. The same applies for the unit of drive train and chassis that can be pre-assembled, which likewise can have a plurality of sequenced constructional units, which are provided and pre-assembled depending on the drive concept of the corresponding motor vehicle.
In line with the engagement, the floor module on one side and the drive train and chassis on the other can then be combined together outside the main assembly line, such that, with respect to this, the main assembly line can be freed of variants at least to the greatest extent possible and thus can be streamlined. As a result of this, a drive-neutral shell arises, which has a particularly advantageous effect on the times and costs of assembly.
Furthermore, due to this method, the expenditure for achieving pearl-necklace-related logistics required for the respective assembly line is considerably reduced.
In a further embodiment of the invention, the chassis and the drive train are, within the corresponding second pre-assembly process, preferably pre-assembled on an auxiliary carrier, which, for example, can be designed as a so-called assembly skid. The chassis and the drive train can be prepared particularly advantageously on this auxiliary carrier for the engagement with the floor module.
A further advantageous embodiment provides that the floor module is placed on the auxiliary carrier. There thus arises a particularly simple and easy-to-assemble connection of the floor module to the drive train and the chassis.
Here, in a further embodiment of the invention, it has been shown to be advantageous if a function test of respective constructional units is carried out after the floor module, the drive train and the chassis have been combined in line with the engagement. Thus, a completion and testing of the components involved can take place before the marriage with the shell of the motor vehicle, which in turn streamlines the main assembly line even further. After the engagement, corresponding working materials can also already be filled in or energy storage devices can be supplied accordingly, such that, in particular, the drive train and the steering and the brakes are already in a state of operational readiness. This provides the advantage that the shell can, if necessary, be made to be ready-to-drive in a simple manner after the combining in line with the marriage, so as to at least partially dispense with external conveyance and transportation technology.
In this way, an extensive function test can be carried out on the vehicles and the components used at a very early point in time before the vehicles reach the main assembly line. Errors and functional defects can be detected and dealt with in a timely manner. Furthermore, consequential defects occurring later can thus be prevented. This contributes to a high level of manufacturing quality.